1. Field of the Invention
The field of the invention is data processing, or, more specifically, methods, apparatuses, and computer program products for controlling communication between whitespace devices.
2. Description of Related Art
In telecommunications, whitespaces refer to frequencies allocated to broadcasting services but not used locally. National and international bodies assign bands for specific uses, and in most cases, license the rights to the spectrum. This frequency allocation process creates a band plan, in which guard bands may be assigned between used radio bands or channels to avoid interference. In addition, there may be unused portions of radio spectrum that have either never been used or are becoming available as a result of technical changes.
In the United States, the Federal Communications Commission (FCC) ruled that unlicensed devices guaranteeing that they will not interfere with assigned broadcasts can use the empty whitespaces in the frequency spectrum. A device intended to use these available channels is often referred as a whitespace device (WSD). A whitespace device may be used to transmit data to another whitespace device over available transmission channels. For example, various proposals, including IEEE 802.22 have advocated using whitespaces left by the termination of analog TV to provide wireless broadband Internet access. The number of transmission channels available to a whitespace device may be dependent upon the coverage area of the whitespace device which is a function of the transmitting power of the whitespace device.
In general, the higher the transmission power of a whitespace device, the greater the coverage area and the higher the throughput the whitespace device can provide. However, in densely populated urban areas, user-base of bandwidth is high and thus the whitespace spectrum available to high transmission power whitespace devices is limited. In this situation, some low transmission power whitespace devices may have more available transmission channels than a high transmission power whitespace device. While the low transmission power whitespace device may have the available transmission channels, the low transmission power whitespace device may not provide enough throughput to meet a user whitespace device's needs. Consequently, selecting a transmitting whitespace device with a high transmission power or a low transmission power may result in one or more performance tradeoffs including insufficient throughput capabilities or an insufficient coverage area.